Left Ventricular Dysfunction, Pulmonary Hypertension, Obesity, and Sleep Apnea

Abstract

The purpose of this study was to determine the frequency of central and obstructive sleep apnea in adult patients who have echocardiographic evidence of left ventricular dysfunction and pulmonary hypertension. Subjects with left ventricular dysfunction, pulmonary hypertension (pulmonary artery systolic pressure >30 mm Hg) and no lung disease were evaluated for risk factors associated with pulmonary hypertension. Of eight eligible adults, six completed the study. Subjects were from suburban and inner city family practices. Spirometric assessment, pulse oximetry on room air, rheumatologic evaluation, polysomnography, and additional history were taken. All six subjects had sleep apnea (apnea-plus-hypopnea index, or AHI, > or = 20): obstructive, central, or mixed. All were obese, and almost all the subjects had a restrictive pattern on spirometry, which is consistent with obesity. All had a pulmonary artery systolic blood pressure of 35 mm Hg or greater. None had daytime hypoxemia or collagen vascular disease, and none had ever used appetite suppressants. This study found a strong association between pulmonary hypertension and obstructive or central sleep apnea in obese patients with congestive heart failure (CHF). We propose that a pulmonary artery systolic pressure of 35 mm Hg or greater in ambulatory patients with CHF may signify an increased risk of sleep apnea.

Obesity and respiratory diseases

“…Several retrospective studies have also found a strong association between OSA and pulmonary hypertension, possibly because of hypoxemia, hypercapnia, and increased sympathetic activity. 119 In a study of 20 ambulatory patients visiting a suburban family practice clinic presenting with unexplained bilateral leg edema and echocardiographic evidence of pulmonary hypertension, almost all the subjects were obese and 60% of them had OSA without evidence of daytime hypoxemia. 120 Currently, there is a paucity of data to support a causal relationship between pulmonary hypertension and obesity.…”